Molds Alum & Brass??

[gandydancer]

Have done no casting for over 10 years or so. Iron molds is all I ever used. tried casting a few today just for fun using a two cavity alum and a four cavity brass. What am I doing wrong? any help would be great, gandy :killingpchttp://castboolits.gunloads.com/imagehosting/thum_66914f3c5b23afda3.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=3962)

http://castboolits.gunloads.com/imagehosting/thum_66914f3c5b522280f.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=3963)

[btroj]

Cold mould. Could be a bit of oil in it too.

[runfiverun]

brass takes more heat than mehanite and aluminum takes more than brass.
they shed heat faster,you need to either cast faster with them to keep the mold up to temp or turn the heat up slightly.
i normally cast betwen 650-700 depending on the steel mold i am using.
with aluminum i go to 700 and up to 725 just to keep my casting pace the same.

[gandydancer]

thanks guys. I will do better next time. GD

[RobS]

The HP pins and hardware can take the heat from a mold too. I have a HP mold that needs warmer alloy than usual and fast casting tempo to keep quality boolits dropping from the mold.

[white eagle]

heat er up you are running cool or slow

[stubshaft]

When I cast HP's I usually don't inspect them until after I am done. It slows me down and that gives me boolits like yours.

[canyon-ghost]

Run faster and hotter, you betcha! Come on along fer the ride!

You can preheat or, just pour a dozen casts getting them up to temperature. The old iron molds taught you right.